About this tool
The Bean Bag Fill Calculator is a free, in-browser tool that estimates how much EPS bead filler a bean-bag chair needs, in cubic feet, liters, and standard 100 L filler bags. Choose the bag shape — teardrop/pear chair, sphere, cylinder, or rectangular — enter the dimensions, and it computes the filler volume you should buy. Everything runs locally in your browser, so nothing you enter is uploaded.
The method first finds the bounding volume by shape: sphere V = (4/3)πr³, cylinder V = πr²h, rectangular V = L × W × H, and a typical teardrop chair as about 70% of its bounding cylinder, 0.7 × πr²h. It then applies a fill factor (default 85%) because bean bags are filled roughly 80–90% full — not solid — so they stay soft and moldable. Filler volume = shape volume × fill factor. Volumes convert to cubic feet (1 ft³ = 28.317 L) and liters, and the tool rounds up to whole 100 L filler bags (a common retail size, about 3 ft³ each). It also shows a settled volume with about 10% extra, since EPS beads compress over time and most chairs need a top-up refill.
As a worked example, a teardrop chair modeled as a 35 in diameter by 40 in tall cylinder has a bounding volume of about 0.7 × π × 17.5² × 40 ≈ 26,900 in³; at 85% fill that is roughly 22,900 in³, about 375 L or 13.3 ft³ — so you would buy four 100 L bags, and budget about 10% more (≈ 413 L) to allow for settling. Larger or firmer chairs need proportionally more, and buying one extra bag makes future top-ups easy.